Answer:
They were very just. The British Government was charging an excessive and unfair amount of taxes on the colonies, taxes that were also quite regressive (meaning that they affected the poor disproportionately).
The colonies were used to a great degree of autonomy and self-rule, and these types of taxes were met with shock and opposition.
At first, the colonists were asking for parliamentary representation as a necessary condition for the imposition of existing and new taxes, but these demands were met with scorn. For this reason, the situation turned into a full revolt, which finally resulted in the American Revolutionary War.